Anti-inflammatory diterpenoid alkaloids from Aconitum tanguticum (Maxim.) Stapf

Fifteen undescribed diterpenoid alkaloids and seven known analogs were coisolated from the whole plant Aconitum tanguticum (Maxim.) Stapf. Their structures were elucidated based on spectroscopic methods. Among them, tangirine A was a heteratisine-hetidine-type bis-diterpenoid alkaloid, tanguticinines A-F were six hetidine-hetisine-type bis-diterpenoid alkaloids, tanguticinine G was one hetidine-atisine-type bis-diterpenoid alkaloid, and N-oxide anthoroidine B, 5-deoxyanthoridine B and N-oxide 5-deoxyanthoroidine B were three unusual hetidine-rearranged hetisine-type bis-diterpenoid alkaloids. In the bioassay, thirteen compounds showed some inhibitory effects on the secretion of NO and TNF-alpha in LPS-treated RAW 264.7 cells, with IC50 values of 67.56 mu M-683.436 mu M.